Electrolytically refining metals.



rrnn sa rps YELECT-ROLYTECALLY nEFmme. METALS.-

Specification of Letters Patent.

Patented. June 18, 1907.

Application filed February 20,1906. Serial No. 246,453.

To all whom/lit may concern:

Be it known that I, Anson GARDNER Bn'r'rs, a citizen of the United States, residing at Troy, in the countyv of Rensselaer and arranger-l for carrying out my invention.

Fig. 2 is a view in elevation showing two electrolytic metal refining tanks, varranged for carrylng out my invention.

This invention relates to a method of lesseningthe amount of anode scrap produced in electrolytic metal refining operations.

Certain objects of my invention are to de -crease the costs and dillicultics in electrolytically refining metals.

In electrolytically refining metals such as copper, to which the anode residue does not ordinarily stick, the anode area in a tank finally becomes reduced while considerable anode copper still remains umhssolved, thus increasing the anode current density, and in certain parts of the cathode surface the cathode current density. As the refinery contains a large number of tanks in the same electrical series, it is not desirable to reduce the current passing for the sake of maintaining a proper current density in one or a few tanks to make pure copper, and as a consequence the anodes are removedfrom the tanks as scrap before they are well used'up. As a preferred means for carrying out my new method. I have provided one or more shunts, with a switch for each, toshunt parof the current around any individual tank, or set of a few tanks, when the anode area becomes reduced. The shunts are preferably of such dimensions that when all the shunts provided for one tank or set of tanks are in use, the resistanceis about the same as that of the tank or tanks when freshly char ed with electrodes. Thus, when the tank is first used, the shunts are disconnected and the current entirely passes through the electro-v lyte. Toward the last, when the anode area begins to diminish considerably, I connect PATENT omen Anson GARDNER BETTS, or TROY, NEW YORK.

a shunt in circuit, and when only a small part of the anode surface is left, all the shunts are used, when the electromotive force at the bus-bars is practically the same as it was at first, and the small anode area remaining is the start. By having two. or more parallel "undergoing electrolysis at the same rate as on shuntsin a set I am able to economize in electric energy, so that the full shunt capacity, with its loss of energy, need not be used, when the anode area has been reduced to, say, only one-half the original area. By

having half the shunt ca )acity in use at this time, the electromotive iorce of the tank or set of tanks is the same as when the tank is charged.

In refining metals, such as lead containing 5% of im urities, the impurities, in which remain stic ring to the anodes, I secure additional advantages. When refining lead, if the current density, and conse uently the'electroniotive force, become too igh, copper, etc., dissolve in the electrolyte, and spoil the oathode lead. Also the anode residue has to be wiped froin the scrap produced by the hitherto used process, but I am now able to dissolve the scrap entirely and do away with.

the wiping process. I need not have shunts arranged for all the tanks in a refinery, may charge those provided with shuntswith anodes already partially dissolved in other tanks. 1

Having reference to the. accompanying andv 'drawings, Fig. 1, l'is a tank, 2 the'po'sitive bus-bar, 3 the negative bus-bar, 4 are anodes, and 5 cathode-supporting bars. Electric connection may be established between the positive and negative bus-bars by one or both of the shunts 6, whenone or both of the 'tswitches 7 are closed.

In Fig. 2 the tanks 1 are'ii tted withbus-bars 2 and 3, and intermediate copper strip 4, which supply the electric "current to the anodes 5, and the cathode-supporting bars 9. Electric connection may be established between the bus-bars 2 and 3 by one or both ofthe shunts 7 when one or both of the switches 8 are closed. After connecting a shunt on a tank or set of tanks, the diminishing area of the anodes has a tendency ofraising the voltage, thus sending an increasing current through the shunts, so that the remaining current passing through the electrolyte is in amount a function of the diminishing area of the anode surface.

which consists in first passin' odes through a suitable electrolyte to suitable What I claim as new and desire to secure by Letters Patent, is:

1. The process of electrolytically refining a set of metal anodes arranged in' multiple,

from said anc'athodes practically the full volume oi" the re finery circuit until the active anode area begins, to diminish largely, and then shunting aroundthe tank containing said anodes, part of the refinery current, which part increases thereafter functionally with the diminishing active anode area. i

2. The process of electrolyticallyrclining a set of metal anodes arranged in multiple,

which consists in passing from said anodes lthrough asuitable electrolyte to suitable l cathodes an electric current of volume which does not change to an appreciable extent functionally with variations of resistance of I the bath, and when the active surface ol said I anodes has been reduced to a considerable l extent shunting through another conductor an increasing portion oi the current. i In testimony whereof I have hereunto set my hand this 16th day of l ebruarv, 1905. l ANSON GARDNER BET'IS. l Witnesses: l l

Fnnonnicic CLARK, EDW'ARI) F. Keys. 

